Accumulators of the aforedescribed type are manufactured by cold deformation of a metal disk in two operations, namely a first operation for obtaining a cylindrical or conical blank whose end has a convex bottom and is provided with an orifice for filling the first chamber with gas and a second operation in which, after the membrane has been fixed in the casing by means of the cup, the cylindrical part of the blank is hammered to give it a spherical shape having an axial orifice in which a connection is crimped and welded for feeding liquid into the second chamber.
Up to now, the cup is fixed to the casing by means of a bolt and nut for, after inflation of the accumulator, tightening the head of the screw against a seal.